User blog comment:MegaGyarados/You Guys NEED, AND I MEAN NEED, to understand this (This isn’t about teams again)/@comment-32358261-20180215091539

The only game the master ball had a chance to fail was in gen 1 with a 1/256 (I think. It might be lower odds)vchance of failing. Since then, master balls have been specifically coded to override the capture rate formula completely and it is 100% impossible unless you literally hacked the game for it to do so